| Competition: | Western Football League |
| Season: | 1920–21 |
| Winners: | Bristol City Reserves (Division One) Peasedown St John (Division Two) |
| Prevseason: | 1919–20 |
| Nextseason: | 1921–22 |
The 1920–21 season was the 24th in the history of the Western Football League.
The Division One champions this season were Bristol City Reserves, for the second time in their history. Champions of Division Two were Peasedown St John, who gained promotion to Division One along with Trowbridge Town.[1]
Eight new clubs joined Division One this season, and the number of clubs increased from 10 to 16 after Horfield United and Newport County Reserves left the league.
Abertillery Town, Mid Rhondda, Pontypridd and Ton Pentre were also members of the Southern League (Welsh section) during this season. All four clubs left the Western League at the end of the season to concentrate on the Southern League.
Three new clubs joined Division Two this season, and the number of clubs increased from eight to ten after Yeovil and Petters United were promoted.